As a process for efficiently developing silver halide photographic materials (hereinafter referred to as photographic materials), a high temperature development, and in particular a high temperature quick processing by an automatic processor, is known, and such has been applied to various kinds of photographic materials with an improved effect. However, because the photographic material is processed at high temperature, it is necessary to increase the physical strength of the silver halide emulsion layers of the photographic material during processing for preventing the emulsion layers from becoming too brittle and thus being damaged by the pressing action of rollers and belts in the automatic processor. Accordingly, a counterplan for increasing and maintaining the physical strength of the emulsion layers in the developer with the progress of the development must be taken. For the purpose, there is a technique of processing which is performed with the addition of a dialdehyde series hardening agent to a developer. This technique of processing is particularly excellent for the quick processing of radiographic lightsensitive materials, and has already been widely used. Such technique of processing is described, for example, in U.S. Pat. No. 3,025,779, British Pat. No. 825,544, Japanese Patent Publication No. 47045/76, etc.
According to this technique of processing, the total processing time is shortened by high temperature processing, and the purposes of quick processing may be attained to some extent, but when the developing process is performed using a developer containing an aldehyde, and particularly an aliphatic dialdehyde as a hardening agent, the formation of fog becomes severe. Furthermore, this tendency is increased with increasing content of silver iodide (particularly a silver iodide content larger than 1.5 mole%) in the silver halide grains of the photographic material. Also, the increase of the content of silver iodide causes not only the severe formation of fog but also the problems of the change of the characteristic curve (e.g., reducing contrast), the deterioration in graininess, etc.
The formation of fog occurring when photographic materials are processed by a developer containing such a dialdehyde series hardening agent can be prevented to some extent by using a strong organic antifoggant such as benzotriazole, 1-phenyl-5-mercaptotetrazole, etc. (see, for example, Photographic Processing Chemistry, L. F. Mason, page 40, etc.), but even by using the foregoing antifoggant, the formation of fog cannot be prevented for photographic materials having a particularly high content of silver iodide (i.e., larger than 1.5 mole% silver iodide).